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J. H. GUEST. Electric Lamp.

No. 233,346. Patented Oct. 19, I880;

N.FETERS, PHOTO-UTHOGHAPHER; WASHINGTON, D, C.

UNITED STATES PATENT OFEicE.

JOHN H. GUEST, OF BROOKLYN, NEW YORK.

ELECTRIC LAM P.

SPECIFICATION forming part of Letters Patent No. 233,346, dated October 19, 1880.

Application filed February 27, 1880.

To all whom "it may concern Be it known that I, JOHN H. GUEs'r, of Brooklyn, in the county of Kings and State of New York, have invented an Improvement in Electric Lamps, of which the following is a specification.

Electric lamps have been made with carbon, platina, and other material in the circuit,

. rendered incandescent by the passage of the current, and such conductors have been placed within a glass bulb that is exhausted of air; and in an application heretofore filed by me cups or receptacles for mercury are made upon the glass of the bulb, and through these the conductors pass.

In all instances where the wires pass through the glass thereis risk of the glass being broken, or of the wire becoming smaller and allowing air to pass between it and the glass. This arises from the wire expanding by heat, and where the glass is strong enough to withstand that expansion the wireis increased in diameter while hot, and when it cools the wire becomes smaller and shrinks away from the glass. The object of the mercury seal is to prevent air passing in between the wire and glass.

My present invention is a still further improvement in the same line. I employ groups of wires, each having two or more very fine wires passing through the glass, and these are bunched or twisted together to form the pairs of conductors, and themercury also is applied as before. By this improvement the electric current is diffused through the two or more fine wires. Hence each wire takes a smaller proportion of the current thanit would if only one conductor were used, and the heat is not as great as heretofore, and the expansion is less in proportion; and as the wires used are so much smaller the expansion is reduced to a minimum.

In the drawings, Figure l is a section of my improved lamp, and Fig. 2 is a section of the glass where the wires pass throughseparately.

The glass bulb a is of usual character, and at b c are the cups for the mercury-seals d e to the metallic conductors f g, and it represents the carbon that is rendered incandescent by the passage. of the electric current.

The carbon is to be connected to the conductors in any desired manner. I have shown the conductors as made into loops, in which the carbon is suspended.

It sometimes happens that the carbon becomes injured and the lamp useless. To guard against this I make a carbon holder, t, of glass, at one side of the bulb a, and in this holder there are carbons in any suitable num' her, and the orifice 0 between a and i allows for one carbon. at a time being shaken into the loops or holders of the conductors without injury to the vacuum in the bulb.

The conductors f and g are each composed of two or more fine wires, for the reasons and with the object before mentioned.

Sometimes I twist the two or more wires together, and pass them in that condition through the glass, as seen in Fig. 1, care being taken to melt the glass into the spaces between the wires. In other instances the wires are in a more open condition, but having suflicient twist to prevent the lengthening of the wires at each surface of the glass, the expansion bein g in the direction of the circumference of the helix. In other instances these very fine wires pass through the glass straight, as seen in Fig. 2, and are afterward twisted or bunched together where they are united to the incandescent conductor, and also within or near the mercury-seal.

In cases where the bulb contains gas that will not injure the incandescent body, said gas is, confined by the mercury-seal, applied, as aforesaid, around the conductors.

I claim as my invention- 1. In an electric lamp, two or more very fine wires passing through the glass and grouped together to form each of the conductors leading to the incandescent light-giving body, for the purposes and substantially as set forth.

2. The combination, with an exhausted glass bulb and the electric conductors, of a carbonholder of glass at one side of the bulb and an opening from the same into the bulb, substantially as set forth.

Signed by me this 26th day of February, A. D. 1880.

J. H. GUEST.

Witnesses:

G130. T. PINCKNEY, WILLIAM G. MOTT. 

